The present invention relates to a film assembly comprising a pair of film containers and a length of film extending therebetween for use in photographic cameras.
The present application is a Continuation-In-Part of U.S. Ser. No. 09/665,132 directed to a mechanism suitable for ensuring film alignment within a camera of film having pre-exposed latent images thereon, and to a camera incorporating such a mechanism, and to a film frame counter resetting mechanism.
It is known to provide photographic film which has been partly exposed in regions of each film frame with an image which is retained as a latent image. The user who loads the film then exposes the film in the normal manner in a specially adapted camera. The camera includes some masking arrangement to mask out the area of the film which bears the latent images, so that these are not double-exposed. When the film has been exposed by the user, it is processed and developed in the normal way, the finished pictures bearing both the pre-exposed images provided by the manufacturer (hereinafter referred to as xe2x80x9cpre-exposed imagesxe2x80x9d), and the user-exposed images thereon. For example, it can be arranged that the film is pre-exposed with a decorative strip which carries a message such as xe2x80x9chappy birthdayxe2x80x9d or xe2x80x9cwish you were herexe2x80x9d, the camera including a strip-like mask in the exposure window to prevent double-exposure of the pre-exposed film region.
It has been previously proposed by the applicant to provide such a film in a package or assembly comprising a standard 35 mm cassette and a second spoolless film container into which the film is wound extending from there to the cassette. Such a film package is disclosed for example in applicant""s U.S. patent application Ser. No. 09/412,460. In use, the assembly is fitted into the camera with the cassette and film container arranged on opposite sides of a film exposure window. As pictures are successively taken the film is progressively wound out of the film container back in the cassette, finally being wound back fully into the cassette which can then be removed by the user for developing and processing. The film container is then discarded.
A particular problem arises with such a film assembly in that during handling either in a factory where a new camera is being loaded with film for the first time, or when a user is loading film themselves there is a risk of damage to the film, such as tearing and buckling. There is also a risk of withdrawal of film from one of the containers if it is inadvertently pulled, or if one of the containers is dropped.
The present invention is directed to providing a structure which mitigates such problems.
According to the present invention there is provided a film assembly comprising a pair of film containers and a length of film extending between the containers and with a major part of the film rolled into one of the containers, wherein a backing sheet of flexible material which overlies the entire film between the containers to the extent that the flexible sheet is shaped to cover the film and block contact with the area of the film in from lateral edges of the film, and the backing sheet is secured to each container to extend therebetween.
This backing sheet provides a protective function in that it overlies the film preventing inadvertent separation of the containers, preventing possible inadvertent film withdrawal and the risk of tearing or other damage, as well as preventing the film from being scratched.
In the preferred embodiment the film containers each define film slots therein through which the film extends, the backing sheet being secured at each end to the respective film containers at a position adjacent the film slots. One of the film containers may be a spoolless container into which, before use, the majority of the film is wound, and with protruding portions provided thereon which engage complementary openings in the backing sheet.
The backing sheet may be secured to the other container by means of adhesive, or an adhesive strip. This container may be a conventional 35 mm film patrone.
An edge region of the backing sheet may be provided with a cut out portion to expose a portion of the edge of the film. This is useful in film alignment in the case of film bearing pre-exposed latent images.
The film assembly may be used in a camera for use with film bearing a series of latent pre-exposed images for subsequent user-exposure, comprising a film sprocket wheel extending into a film passageway, the sprocket wheel comprising a wheel having a plurality of equidistantly-spaced teeth one of which is visually distinguishable from the other teeth. The alignment tooth may be formed of a different colour to the other teeth, either by painting the alignment tooth or moulding it of a different coloured plastics material. The sprocket wheel may comprise a main wheel part on which said other teeth are formed, and said alignment tooth is formed of a separate part securable to said main wheel part. These may be formed of moulded plastics parts where the plastics are of contrasting colours. The main wheel part may define a part-annular recess, and the alignment tooth extends from a part-annular insert receivable in said recess. The sprocket wheel may be operatively connected to a shutter mechanism and wind-on mechanism where rotation of the sprocket wheel is arranged to effect re-cocking of the shutter mechanism. The wind-on mechanism prevents rotation of the sprocket wheel when the shutter is re-cocked. In the re-cocked state of the shutter mechanism the alignment tooth extends rearwardly within the camera towards the film passageway.
A method of loading film bearing a series of pre-exposed latent images for subsequent user-exposure into a camera as described above having a film sprocket wheel operatively connected to a shutter mechanism and provided with a film alignment tooth, comprises the steps of: a) opening the camera back; b) rotating the film sprocket wheel until the film alignment tooth thereof extends towards the film passageway, and until the shutter mechanism is re-cocked; c) inserting film into the camera so that an alignment mark on the film is aligned with the alignment tooth; and d) closing the camera back.
The camera may also have a pair of film-receiving chambers arranged on opposite sides of an exposure window between which, in use, film extends through a film passageway: a film sprocket wheel having a plurality of teeth which, in use, engage a film extending within the film passageway; a film counter drive wheel operatively connected to the film sprocket wheel driven by rotation of the sprocket wheel; a pivotably mounted film frame counter wheel mounted on a displaceable pivot engageable with the drive wheel; and resilient means which urge the film frame counter wheel to a reset position in which the film frame counter wheel adopts a predefined orientation.